Have a diagram? It's important to not only measure the lowest point but also how much hangs low. The Currie 60 has a very small amount that actually hangs low.
A dumptruck axle will also be stronger. In the context of TJs, this thread, and what just about everyone here is doing they won't need stronger.
Unless you're finding a junkyard axle somebody already built how you want it (meaning you get a really good price on the locker, gears, etc), your only difference in price is going to be the bare housing since you still need to buy the gears, lockers, etc.